In manufacturing and other operations, a roll of material may need to be mounted onto or off a roll. In some applications, particularly in the paper industry, such as with the manufacturing of paper towels, it is desirable to include a core plug in either end of the core. Once the core plugs are mounted into the core, the core plugs are then mounted to a roll stand, which fits into the journals of the core plugs.
Core plugs must have high strength, to withstand both the forces to which they are subjected during normal use and the forces that result from the core plugs being dropped during insertion or removal from a core. Also, they should be easy to assemble and insert into a core.
Existing core plugs tend to be heavy (typically, approximately 80 pounds), inconvenient to use and to assemble, and to have inadequate durability.
In some cases, existing core plugs take the form of a plastic plug with a separate steel tube that fits into the center of the plug at its outer end and a steel journal. These plugs tend to be heavy. Moreover, the tube tends to wear out the inside of the plastic plug. In other cases, existing core plugs are made from aluminum, with an aluminum plug and an aluminum tube, but these tend to fail from metal fatigue, abuse, or other causes and can be very heavy.